This invention relates to gear shift lever assemblies for vehicles and, in particular, to gear shift lever assemblies adapted to prevent theft of vehicles.
The problem of vehicle theft in the United States and elsewhere is a significant one. This has led to a variety of devices which attempt make theft more difficult. Some of these devices comprise expensive electronic systems such as, for example, electronic alarm systems, which are incorporated into a vehicle and which sound an alarm when unauthorized attempts are made to enter the vehicle. Others of these devices are less costly mechanical devices such as, for example, steering wheel collars or crook locks which lock parts of the vehicle and prevent their use unless unlocked by an authorized person having a key.
Another type of mechanical device which has been proposed is a removable gear shift lever. This type of device allows you to remove the vehicle gear shift lever from the vehicle when it is unattended. As a result, a potential thief not seeing the gear shift lever will be less likely to attempt to steal the vehicle. Also, the absence of the gear shift lever makes it much more difficult for a thief to steal the vehicle, even if the thief is not deterred by visually observing that the gear shift is not present.
Removable gear shift levers are disclosed in a number of prior art patents. U.S. Pat. No. 1,398,455 discloses a gear shift lever in which the lower end of the gear shift lever is modified so as to be removably engageable with a suitably adapted end of the automobile gear shift mechanism. In one form of the gear shift lever of the '455 patent, the lower end of the lever is a solid shaft provided with a lug. The latter is then engageable with a bayonet slot of a tubular shaft in the gear shift mechanism. In other forms of this device, the shaft of the gear shift mechanism is formed as a rod. In one case, the lower end of the gear shift lever is made tubular so as to tightly fit around this rod. In another case, the rod is externally threaded and the tubular end of the lever is internally threaded so that the lever can be screwed onto the externally threaded rod.
U.S. Pat. No. 2,293,197 discloses another type of gear shift lever assembly in which the gear shift lever is screwed into a support member which can be detachably mounted to a part of a gear shift mechanism. In this gear shift assembly, the support member comprises a first part which is welded to the gear shift mechanism and a second part which carries the gear shift lever. This second part also carries a lock which can be locked and unlocked with a key to attach and detach the second part and, therefore, the gear shift lever from the first part. This allows the gear shift lever to be removed from the vehicle.
In U.S. Pat. No. 3,564,878 a further type of removable gear shift lever assembly is described in which one end of the gear shift lever is provided with a key which is followed by a threaded cylindrical surface and a tapered cylindrical surface. In this case, the shift column of the gear shift mechanism of the vehicle is provided with a threaded cylindrical hole followed by a cavity which carries a cylindrical lock. A cover plate covers the shift column and has a tapered bore which aligns with the threaded cylindrical hole. The gear shift mechanism also has, internal of the shift column, a rotatable member having an aperture which aligns with the cylindrical lock.
With this gear shift assembly, the key end of the gear shift lever is inserted through the tapered bore of the cover plate and through the threaded cylindrical surface of the shift column to engage the cylindrical lock. At this position, the threaded cylindrical surface and the tapered cylindrical surface of the lever engage the threaded hole of the shift column and the tapered bore of the cover plate, respectively. Rotation of the lever then causes the key to rotate the cylindrical lock, thereby allowing its cylindrical plug to enter the associated aperture in rotatable member of the gear shift mechanism. In this way, the gear shift lever is held to the column so that movement of the lever allows shifting of the gear shift mechanism. By rotation of the gear shift lever in the opposite direction, the lever is removed from the shift column.
The above-described removable gear shift levers have certain characteristics which detract from their usefulness. In particular, each is such that the gear shift lever can be removed in any shift position of the automobile. This can occur with the levers of the '455 and '878 patents by rotating the levers to disengage them from the gear shift mechanism. In the lever of the '197 patent, on the other hand, the key can be used to unlock the second part of the support member to detach this member and, hence, the gear shift lever.
As a result, it is possible to remove each of these levers when in a shift position in which the vehicle can move. This tends to compromise the safety of the vehicles in which the levers are used. Also, in the gear shift levers of '197 and '878 patents locks are required, making these levers overly complicated and expensive.
It is, therefore, an object of the present invention to provide a removable vehicle gear shift lever assembly which does not suffer from the above drawbacks.
It is a further object of the present invention to provide a removable vehicle gear shift lever assembly in which the assembly can be more safely used.
It is yet a further object of the present invention to provide a removable vehicle gear shift lever assembly which is secure without the need of expensive locks.